No sound device on MacBook Pro

Hi all,

This is my first time posting here, hope someone can help..thanks..

I do not have any audio output on my Macbook Pro when running on mac os. However, there is still the start up chime sound. It shows a stop sign when I tried to increase or decrease the volume. Sound panel shows 'no audio output'. No red led light from the headphone jack as well.

My MacBook Pro details are as follow:
Mac OS X Version 10.7.5

TEG said:

Have you tried Restarting?

Is there a red light coming out of your headphone jack?

Do you have sound when booting into Safe Mode (Holding Shift)?

Click to expand...

I've tried restarting a few times already.
No red light on headphone jack
I've even tried resetting NVRAM

Still the same... What should I do?

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MagicBoy said:

£0.02 says it's the red light issue....

Click to expand...

It's not red light issue.
It happened before but solved by resetting NVRAM. But this case, I reset NVRAM but still can't solve the prob.

NazzibsamaD said:

I've tried restarting a few times already.
No red light on headphone jack
I've even tried resetting NVRAM

Still the same... What should I do?

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It's not red light issue.
It happened before but solved by resetting NVRAM. But this case, I reset NVRAM but still can't solve the prob.

Click to expand...

Currently...
My MacBook Pro detected the sound. All I did was...

shut down
switch on to safe mode
shut down
switch on resetting NVRAM (pressing Option, Command, P and R while switch on)

then the volume and sound control has been detected and working as usual...

Thx...

NocturnalJazz said:

Do you have "Boom" installed on this machine?

Click to expand...

Nope.